This invention relates to bus bar connectors and, more particularly, to such connectors which are utilized in power distribution systems and which include a coating of water-impervious material to provide an insulated and waterproof connection.
Bus bar connectors including an elongated bus bar having a plurality of transversely projecting terminals for attachment to the flexible conductors of a power distribution system are known and have been widely used in the art. Bus bar connectors of this type are exemplified in U.S. Pat. No. 3,480,905, which is assigned to the same assignee as the present invention. In the prior art, these bus bars all have terminals extending from a solid common bar such as a casting or a machined workpiece. These bus bar connectors are generally divided into two types depending on the terminal configuration. In the first, a flat tang accommodates a terminal lug attached to the tang by means of a threaded fastener such as a bolt. The other type includes a bore within the terminal, such as that provided by a core during the casting operation, and a set screw projecting into the bore through a second (threaded) bore extending transversely of the first bore.
These prior art devices are heavy and overdesigned in that the cross-sectional area of the bus bar is typically substantially greater than the cross-sectional area of the maximum conductor for which the bus bar connector was designed. That is, the excess material not only contributes to the weight of device but also needlessly adds expensive handling problems. Moreover, the casting operation gives rise to porosity and shrinkage problems on the external surfaces of the completed casting. That is, due to the large mass of a typical bus bar connector, shrinkage and surface porosity problems are encountered during the cooling operation of the casting process. Since these bus bar connectors are intended to be used in a sealed and insulated environment they are coated with water-impervious insulating material such as PVC. Accordingly, those completed casting exhibiting porosity and shrinkage problems are not suitable for the subsequent coating operation and hence a high reject rate in the operation of applying the insulation to the bus bar connectors has been experienced.
These and other disadvantages are overcome by the present invention wherein a bus bar connector is provided for use with cable conductors of a power distribution system wherein the bus bar is provided as a hollow device wherein the cross-sectional area of the wall portion of the connector are still at least as great as the corresponding cross-sectional area of the respective connectors but which the weight, expense, porosity and shrinkage problems are avoided.